/* crypto/evp/evp_enc.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as CrLONG32 as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include "crypto/CrConfig.h"





#ifdef ISEC_API_BLOCK_CIPHER

//#include <stdio.h>

#include "crypto/CrSMemMgr.h"

#include "crypto/CrEvp.h"



// CrINT8 *EVP_version="EVP part of SSLeay 0.9.0b 29-Jun-1998";



void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
{

	SMemset(ctx,0,sizeof(EVP_CIPHER_CTX));

	/* ctx->cipher=NULL; */

}


void EVP_CipherInit(
	EVP_CIPHER_CTX*	ctx,
	EVP_CIPHER*		data,
	CrUINT8*		key,
	CrUINT8*		iv,
	CrINT32			enc)
{
	if (enc)
		EVP_EncryptInit(ctx,data,key,iv);

	else	
		EVP_DecryptInit(ctx,data,key,iv);
}



void EVP_CipherUpdate(
	EVP_CIPHER_CTX*	ctx,
	CrUINT8*		out,
	CrINT32*		outl,
	CrUINT8*		in,
	CrINT32			inl)
{
	if (ctx->encrypt)
		EVP_EncryptUpdate(ctx,out,outl,in,inl);

	else
		EVP_DecryptUpdate(ctx,out,outl,in,inl);
}



CrINT32

EVP_CipherFinal(

	EVP_CIPHER_CTX*	ctx,

	CrUINT8*		out,

	CrINT32*		outl)

{

	if (ctx->encrypt)

	{

		EVP_EncryptFinal(ctx,out,outl);

		return(1);

	}

	else

		return(EVP_DecryptFinal(ctx,out,outl));

}



void

EVP_EncryptInit(

	EVP_CIPHER_CTX*	ctx,

	EVP_CIPHER*		cipher,

	CrUINT8*		key,

	CrUINT8*		iv)

{

	if (cipher != NULL)

		ctx->cipher=cipher;

	ctx->cipher->init(ctx,key,iv,1);

	ctx->encrypt=1;

	ctx->buf_len=0;

}



void

EVP_DecryptInit(

	EVP_CIPHER_CTX*	ctx,

	EVP_CIPHER*		cipher,

	CrUINT8*		key,

	CrUINT8*		iv)

{

	if (cipher != NULL)

		ctx->cipher=cipher;

	ctx->cipher->init(ctx,key,iv,0);

	ctx->encrypt=0;

	ctx->buf_len=0;

}





void

EVP_EncryptUpdate(

	EVP_CIPHER_CTX*	ctx,

	CrUINT8*		out,

	CrINT32*		outl,

	CrUINT8*		in,

	CrINT32			inl)

{

	CrINT32 i,j,bl;



	i=ctx->buf_len;

	bl=ctx->cipher->block_size;

	*outl=0;

	if ((inl == 0) && (i != bl))

		return;

	if (i != 0)

	{

		if (i+inl < bl)

		{

			SMemcpy(&(ctx->buf[i]),in,inl);

			ctx->buf_len+=inl;

			return;

		}

		else

		{

			j=bl-i;

			if (j != 0)

				SMemcpy(&(ctx->buf[i]),in,j);

			ctx->cipher->do_cipher(ctx,out,ctx->buf,bl);

			inl-=j;

			in+=j;

			out+=bl;

			*outl+=bl;

		}

	}



	i=inl%bl; /* how much is left */

	inl-=i;



	if (inl > 0)

	{

		ctx->cipher->do_cipher(ctx,out,in,inl);

		*outl+=inl;

	}



	if (i != 0)

		SMemcpy(ctx->buf,&(in[inl]),i);



	ctx->buf_len=i;

}



void

EVP_EncryptFinal(

	EVP_CIPHER_CTX*	ctx,

	CrUINT8*		out,

	CrINT32*		outl)

{

	CrINT32 i,n,b,bl;



	b=ctx->cipher->block_size;
//	printf("block size: %d \n", ctx->cipher->block_size);
//	printf("b size: %d \n", b);

	if (b == 1)

	{

		*outl=0;

		return;

	}

	bl=ctx->buf_len;

	n=b-bl;

	for (i=bl; i<b; i++)

		ctx->buf[i]=(CrUINT8)n;

	ctx->cipher->do_cipher(ctx,out,ctx->buf,b);

	*outl=b;
}





void

EVP_DecryptUpdate(

	EVP_CIPHER_CTX*	ctx,

	CrUINT8*		out,

	CrINT32*		outl,

	CrUINT8*		in,

	CrINT32			inl)

{

	CrINT32 b,bl,n;

	CrINT32 keep_last=0;



	*outl=0;

	if (inl == 0) return;



	b=ctx->cipher->block_size;

	if (b > 1)

	{

		/* Is the input a multiple of the block size? */

		bl=ctx->buf_len;

		n=inl+bl;

		if (n%b == 0)

		{

			if (inl < b) /* must be 'just one' buff */

			{

				SMemcpy(&(ctx->buf[bl]),in,inl);

				ctx->buf_len=b;

				*outl=0;

				return;

			}

			keep_last=1;

			inl-=b; /* don't do the last block */

		}

	}



	EVP_EncryptUpdate(ctx,out,outl,in,inl);



	/* if we have 'decrypted' a multiple of block size, make sure

	 * we have a copy of this last block */

	if (keep_last)

	{

		SMemcpy(&(ctx->buf[0]),&(in[inl]),b);

#ifdef DEBUG

		if (ctx->buf_len != 0)

		{

			exit(1);

		}

#endif

		ctx->buf_len=b;

	}

}





#if defined(WTLS) || defined(TLS)

CrINT32

EVP_DecryptFinal(

	EVP_CIPHER_CTX*	ctx,

	CrUINT8*		out,

	CrINT32*		outl)

{

	CrINT32 i,b;

	CrINT32 n;



	*outl=0;

	b=ctx->cipher->block_size;

	if (b > 1)

	{

		if (ctx->buf_len != b)

		{

//			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);

			return(0);

		}

		EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0);

		if (n != b)

			return(0);

/*

		n=ctx->buf[b-1];

		if (n > b)

		{

//			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);

			return(0);

		}

		for (i=0; i<n; i++)

		{

			if (ctx->buf[--b] != n)

			{

//				EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);

				return(0);

			}

		}

		n=ctx->cipher->block_size-n;

*/

		for (i=0; i<n; i++)

			out[i]=ctx->buf[i];

		*outl=n;



	}

	else

	{

		return (0);

	}



	return(1);

}

#else // else of #if defined(WTLS) || defined(TLS)

CrINT32

EVP_DecryptFinal(

	EVP_CIPHER_CTX*	ctx,

	CrUINT8*		out,

	CrINT32*		outl)

{

	CrINT32 i,b;

	CrINT32 n;



	*outl=0;

	b=ctx->cipher->block_size;

	if (b > 1)

	{

		if (ctx->buf_len != b)

		{

//			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);

			return(0);

		}

		EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0);

		if (n != b)

			return(0);

		n=ctx->buf[b-1];

		if (n > b)

		{

//			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);

			return(0);

		}

		for (i=0; i<n; i++)

		{

			if (ctx->buf[--b] != n)

			{

//				EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);

				return(0);

			}

		}

		n=ctx->cipher->block_size-n;

		for (i=0; i<n; i++)

			out[i]=ctx->buf[i];

		*outl=n;

	}

	else

		*outl=0;



	return(1);

}

#endif // #if defined(WTLS) || defined(TLS)







void

EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)

{

	if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))

		c->cipher->cleanup(c);



	SMemset(c,0,sizeof(EVP_CIPHER_CTX));

}



#endif // end of #ifdef ISEC_API_BLOCK_CIPHER
